The present invention relates to a liquid crystal display with a switchable view angle.
The publication xe2x80x9cDevelopment of a Dual Domain TFT-LCD Biocomptable Paterningxe2x80x9d (H Klausmann, et al, SID Digest of Technical Papers, 1998 Anaheim, USA), discloses a liquid crystal display with dual-domain liquid crystal cells. With this dual domain liquid crystal cells, an individual viewpoint element is subdivided into two zones. In these zones, the liquid crystal has a different orientation. Thereby the view angle region of the liquid crystal display is expanded.
Accordingly, it is an object of the present invention to provide a liquid crystal display which has advantage that the individual zones of an image point element which have different orientation are controllable electrically separately. Therefore for the liquid crystal display, uniformly designed image point elements are arranged near one another.
Identically oriented zones of an image point element have the same view angle. This view angle is limited only right with an orientation direction of the liquid crystals. This means however that from different image angle regions of the inventive liquid crystal display, exclusively one image is visible, which is produced by the image element zones of only one liquid crystal orientation. In accordance with the present invention, in contrast to the prior art, these individual zones are controlled electronically separately. Thereby it is possible to make visible simultaneously different images in different image angle regions.
The possibility to perform the electrical control via different column conductors, different line conductors or via a subdivision of the front plane electrode allows an adaptation of the desired layout of the image element. Further, an adaptation of the use driver and the control circuit is possible. It should be also noted that the line driver as a rule is more favorable than the column driver.
It is further advantageous that, in addition to the possibility to see two different images simultaneously from two different viewing directions, there are other illustration possibilities. On the one hand, it is possible to switch the liquid crystal display for one view direction to be dark or bright, or in other words to show no image information. From the other image direction an image information can be recognized. Further, there is a possibility for both viewing directions to show the same image information.
In a limiting view angle region, in which at least two different image informations are visible, there is firstly the possibility to provide a stereoscopic image information. This is advantageous for example for the three dimensional representation of a land map, for example for the use in connection with a navigation system.
The rear illumination through two correspondingly modified light conductors, with two different light sources provides the advantage of a separated rear illustration for individual image point elements. It is therefore for example possible that each observer of the can individually regulate the display brightness for its view angle region.